WINNIPEG - A 12-year-old boy is facing charges that include arson after a fire that forced an evacuation in a Winnipeg neighbourhood.

The blaze Tuesday was set inside a large culvert that runs beneath Portage Avenue in the city's west end.

Investigators say the flames spread to the lining made of foam and poly material.

A huge cloud of smoke forced officials to close Portage Avenue and order some businesses to close their doors.

Damage is estimated at $500,000.